Smart pointer wrapper for IBaseObject interface and its descendants. More...

Detailed Description

template<typename T>
class ObjectPtr< T >

Smart pointer wrapper for IBaseObject interface and its descendants.

Smart pointer is an object that wraps IBaseObject and its derived interfaces. It provides automatic reference counting for wrapped interface, data type conversion, comparison and querying for other supported interfaces.

Public Member Functions
	ObjectPtr ()
	Creates a smart pointer with no wrapped interface.

	ObjectPtr (std::nullptr_t)
	Creates a smart pointer with no wrapped interface.

	ObjectPtr (const ObjectPtr< T > &objPtr)
	Creates a smart pointer from another smart pointer. More...

	ObjectPtr (ObjectPtr< T > &&objPtr) noexcept
	Creates a smart pointer from another smart pointer with move semantics. More...

template<class U >
	ObjectPtr (const ObjectPtr< U > &objPtr)
	Creates a smart pointer from another smart pointer of a different interface type. More...

template<class U >
	ObjectPtr (ObjectPtr< U > &&objPtr)
	Creates a smart pointer from another smart pointer of a different interface type with move semantics. More...

	ObjectPtr (T *&obj)
	Creates a smart pointer from an interface pointer. More...

	ObjectPtr (T *&&obj)
	Creates a smart pointer from an interface pointer with move semantics. More...

	ObjectPtr (IWeakRef *obj)
	Creates a smart pointer from a weak reference interface pointer. More...

	ObjectPtr (const wchar_t *value)
	Creates a string object smart pointer from UTF16 null terminated sequence. More...

	ObjectPtr (ConstCharPtr value)
	Creates a string object smart pointer from UTF8 null terminated sequence. More...

template<typename U , std::enable_if_t< is_ct_conv< U >::value &&!std::is_enum_v< U >, int > = 0>
	ObjectPtr (const U &value)
	Creates a smart pointer wrapper from value type. More...

virtual	~ObjectPtr ()
	Destructor. More...

bool	equals (ObjectPtr< IBaseObject > other) const
	Compares object to another object for equality. More...

T *	detach ()
	Disassociates this smart pointer object from the interface that it represents. More...

void	dispose () const
	Disposes all references held by the object. More...

void	release ()
	Resets the wrapped interface to nullptr. More...

T *	addRefAndReturn () const
	Increments the reference count and returns the interface. More...

	operator T* () const
	Casts the pointer to the wrapped interface. More...

bool	assigned () const
	Checks if the smart pointer is not empty.

T *	getObject () const
	Gets the pointer to the wrapped interface. More...

T **	addressOf ()
	Gets the address of the pointer to the wrapped interface. More...

T **	operator& ()
	Gets the address of the pointer to the wrapped interface. More...

template<class U >
U *	as (bool borrow=false) const
	Casts the wrapped interface to another interface. More...

template<class U >
U *	asOrNull (bool borrow=false) const
	Casts the wrapped interface to another interface. More...

template<class U , class Ptr = typename InterfaceToSmartPtr<U>::SmartPtr>
Ptr	asPtr (bool borrow=false) const
	Casts the wrapped interface to another interface and wraps in a smart pointer. More...

template<class U , class Ptr = typename InterfaceToSmartPtr<U>::SmartPtr>
Ptr	asPtrOrNull (bool borrow=false) const
	Casts the wrapped interface to another interface and wraps in a smart pointer. More...

template<class U >
bool	supportsInterface () const
	Checks if the wrapped interface supports another interface. More...

bool	supportsInterface (const IntfID &id) const
	Checks if the wrapped interface supports another interface using the interface ID. More...

CoreType	getCoreType () const
	Gets the object's `CoreType`. More...

ObjectPtr< IBaseObject >	convertTo (CoreType ct) const
	Converts the object to the specified `CoreType`. More...

SizeT	getHashCode () const
	Returns hash code of the object. More...

ObjectPtr< IString >	toString () const
	Converts the object to the string object. More...

void	freeze () const
	Freezes the object. More...

Bool	isFrozen () const
	Checks if the object is frozen. More...

void	dispatch (const ObjectPtr< IBaseObject > &params) const
	Calls the stored callback. More...

void	dispatch () const
	Calls the stored callback without any parameters. More...

void	execute () const
	Calls the stored callback without any parameters. More...

template<typename... Params>
void	execute (Params... params) const
	Calls the stored callback. More...

template<typename... Params>
ObjectPtr< IBaseObject >	call (Params... params) const
	Calls the stored callback and returns the result. More...

bool	isBorrowed () const
	Checks if the reference is borrowed. More...

Static Public Member Functions
template<class U = T>
static InterfaceToSmartPtr< U >::SmartPtr	Borrow (T *&obj)
	Borrows an interface. More...

template<typename U = T>
static InterfaceToSmartPtr< U >::SmartPtr	Adopt (T *obj)
	Adopts an interface. More...

template<class U , class V = T, std::enable_if_t< std::is_base_of_v< IBaseObject, U >, int > = 0>
static InterfaceToSmartPtr< V >::SmartPtr	Borrow (U *&obj)
	Borrows an interface from the interface of another type. More...

static Bool	Equals (const ObjectPtr< IBaseObject > &a, const ObjectPtr< IBaseObject > &b)
	Value based comparison of two objects. If both objects are nullptr, they are considered to be equal. More...

Constructor & Destructor Documentation

◆ ObjectPtr() [1/10]

ObjectPtr ( const ObjectPtr< T > & objPtr )

Creates a smart pointer from another smart pointer.

Parameters

objPtr The source smart pointer with the same type of wrapped interface.

◆ ObjectPtr() [2/10]

ObjectPtr ( ObjectPtr< T > && objPtr )

noexcept

Creates a smart pointer from another smart pointer with move semantics.

Parameters

objPtr The source smart pointer with the same type of wrapped interface.

Source smart pointer is moved into the smart pointer. The Reference count is not incremented.

◆ ObjectPtr() [3/10]

ObjectPtr ( const ObjectPtr< U > & objPtr )

Creates a smart pointer from another smart pointer of a different interface type.

Parameters

objPtr The source smart pointer with a different type of wrapped interface.

◆ ObjectPtr() [4/10]

ObjectPtr ( ObjectPtr< U > && objPtr )

Creates a smart pointer from another smart pointer of a different interface type with move semantics.

Parameters

objPtr The source smart pointer with a different type of wrapped interface.

Source smart pointer is moved into the smart pointer. The Reference count is not incremented.

◆ ObjectPtr() [5/10]

ObjectPtr ( T *& obj )

Creates a smart pointer from an interface pointer.

Parameters

obj	The interface pointer.

The reference count is incremented.

◆ ObjectPtr() [6/10]

ObjectPtr ( T *&& obj )

Creates a smart pointer from an interface pointer with move semantics.

Parameters

obj	The interface pointer.

The reference count is not incremented.

◆ ObjectPtr() [7/10]

ObjectPtr ( IWeakRef * obj )

Creates a smart pointer from a weak reference interface pointer.

Parameters

obj	The weak reference interface pointer.

If the object that the weak reference interface pointer represents does not exist anymore, the smart pointer sets the wrapped interface to nullptr.

◆ ObjectPtr() [8/10]

ObjectPtr ( const wchar_t * value )

Creates a string object smart pointer from UTF16 null terminated sequence.

Parameters

value The UTF16 null terminated sequence.

◆ ObjectPtr() [9/10]

ObjectPtr ( ConstCharPtr value )

Creates a string object smart pointer from UTF8 null terminated sequence.

Parameters

value The UTF8 null terminated sequence.

◆ ObjectPtr() [10/10]

ObjectPtr ( const U & value )

Creates a smart pointer wrapper from value type.

Parameters

value The value.

Value can be any type that has interface wrapper, such as Int, Bool, Float, uint16_t, float, double, etc...

◆ ~ObjectPtr()

~ObjectPtr

virtual

Destructor.

If the interface is not borrowed it releases the reference.

Member Function Documentation

◆ addRefAndReturn()

T * addRefAndReturn

Increments the reference count and returns the interface.

Call addRefAndReturn to return internally stored interface as the function return value. The caller is responsible for releasing returned interface.

Example:

class SomeClass
{
public:
    BaseObjectPtr obj;
}
 
IBaseObject* SomeClass::createObject()
{
    return obj.addRefAndReturn();
}

◆ addressOf()

T ** addressOf

Gets the address of the pointer to the wrapped interface.

Returns: The address of the pointer to the interface.

◆ Adopt()

InterfaceToSmartPtr< U >::SmartPtr Adopt ( T * obj )

static

Adopts an interface.

Parameters

obj	The source interface.

The smart pointer does not increment the reference count when it adopts the interface. However, the smart pointer takes ownership of the interface and releases the interface when it is destroyed. After the interface is adopted, the client should not call any methods directly on the interface.

◆ as()

U * as ( bool borrow = false ) const

Casts the wrapped interface to another interface.

Parameters

borrow Increments the reference count if false, keeps the reference count otherwise.

Throws an exception if cast fails.

◆ asOrNull()

U * asOrNull ( bool borrow = false ) const

Casts the wrapped interface to another interface.

Parameters

borrow Increments the reference count if false, keeps the reference count otherwise.

If cast fails, the wrapped interface set to nullptr.

◆ asPtr()

Ptr asPtr ( bool borrow = false ) const

Casts the wrapped interface to another interface and wraps in a smart pointer.

Parameters

borrow Increments the reference count if false, keeps the reference count otherwise.

Throws an exception if cast fails.

◆ asPtrOrNull()

Ptr asPtrOrNull ( bool borrow = false ) const

Casts the wrapped interface to another interface and wraps in a smart pointer.

Parameters

borrow Increments the reference count if false, keeps the reference count otherwise.

If cast fails, the wrapped interface set to nullptr.

◆ Borrow() [1/2]

InterfaceToSmartPtr< U >::SmartPtr Borrow ( T *& obj )

static

Borrows an interface.

Parameters

obj	The source interface.

The smart pointer does not increment the reference count when it borrows the interface. It also does not decrement the reference count when the smart pointer is destroyed. The client is responsible that it keeps the object alive during the lifetime of the smart pointer.

◆ Borrow() [2/2]

InterfaceToSmartPtr< V >::SmartPtr Borrow ( U *& obj )

static

Borrows an interface from the interface of another type.

Parameters

obj	The source interface.

The smart pointer does not increment the reference count when it borrows the interface. It also does not decrement the reference count when the smart pointer is destroyed. The client is responsible that it keeps the object alive during the lifetime of the smart pointer.

◆ call()

ObjectPtr< IBaseObject > call ( Params... params ) const

Calls the stored callback and returns the result.

Parameters

params Parameters passed to the callback.

Returns: Result wrapped in a smart pointer.

If it does not support the IFunction interface, it throws an exception.

Params are of supported Core types type which is internally converted to it's object representation.

◆ convertTo()

ObjectPtr< IBaseObject > convertTo ( CoreType ct ) const

Converts the object to the specified CoreType.

Returns: ct CoreType of the converted object.

◆ detach()

T * detach

Disassociates this smart pointer object from the interface that it represents.

The reference count is not decremented nor incremented.

Use this function when the object is created in a function and the function returns the interface to the object.

If the object is created outside of the function and the function returns the interface, use addRefAndReturn

Example:

IBaseObject* createObject()
{
    // create smart pointer with wrapped IBaseObject interface
    auto obj = BaseObject();
    // return wrapped interface, the reference count is not decremented
    return obj.detach();
}

◆ dispatch() [1/2]

void dispatch

Calls the stored callback without any parameters.

If it does not support the IProcedure interface, it throws an exception.

◆ dispatch() [2/2]

void dispatch ( const ObjectPtr< IBaseObject > & params ) const

Calls the stored callback.

Parameters

params Parameters passed to the callback.

If it does not support the IProcedure interface, it throws an exception.

If the callback expects no parameters, the params parameter has to be nullptr. If it expects a single parameter, pass any openDAQ object as the params parameter. If it expects multiple parameters, pass a list of openDAQ objects as the params parameter.

◆ dispose()

void dispose

Disposes all references held by the object.

An object that holds references to other interfaces must reset these references to null in dispose. This method is called automatically when the reference count drops to zero.

Call this method manually to break cycle references. If two objects have reference to each other, calling dispose will break cycle references.

After dispose is called, the object should not be accessed again, except by calling releaseRef function.

◆ Equals()

Bool Equals	(	const ObjectPtr< IBaseObject > &	a,
		const ObjectPtr< IBaseObject > &	b
	)

inlinestatic

Value based comparison of two objects. If both objects are nullptr, they are considered to be equal.

Parameters

a	Object to compare.
b	Object to compare.

◆ equals()

bool equals ( ObjectPtr< IBaseObject > other ) const

Compares object to another object for equality.

Parameters

other Interface to another object for comparison.

Returns: The value true indicating if the other is equivalent to this one otherwise false.

For reference objects, it compares the address of the object. For value objects, such as numbers and strings, it compares values.

ImplementationOf which provides default implementation of IBaseObject uses pointer address to compare for equality.

◆ execute() [1/2]

void execute

Calls the stored callback without any parameters.

If it does not support the IProcedure interface, it throws an exception.

◆ execute() [2/2]

void execute ( Params... params ) const

Calls the stored callback.

Parameters

params Parameters passed to the callback.

If it does not support the IProcedure interface, it throws an exception.

Params are of supported Core types type which are internally converted to their object representation.

◆ freeze()

void freeze

Freezes the object.

Function freezes the object if it supports the IFreezable interface. Otherwise, it throws an exception.

Freezing the object makes it immutable.

◆ getCoreType()

CoreType getCoreType

Gets the object's CoreType.

Returns: CoreType of the object.

If the object does not support ICoreType interface, ctObject is returned as CoreType.

◆ getHashCode()

SizeT getHashCode

Returns hash code of the object.

Returns: Hash code Hash code.

◆ getObject()

T * getObject

Gets the pointer to the wrapped interface.

Returns: The pointer to the interface.

◆ isBorrowed()

bool isBorrowed

Checks if the reference is borrowed.

Returns: Result True if it is a borrowed reference.

◆ isFrozen()

Bool isFrozen

Checks if the object is frozen.

Return values

True	The object is frozen.
False	The object is not frozen.

Function freezes the object if it supports the IFreezable interface. Otherwise, it throws an exception.

If it does not support the IFreezable interface, it throws an exception.

◆ operator T*()

operator T*

Casts the pointer to the wrapped interface.

Returns: The pointer to the interface.

◆ operator&()

T ** operator&

Gets the address of the pointer to the wrapped interface.

Returns: The address of the pointer to the interface.

◆ release()

void release

Resets the wrapped interface to nullptr.

If the smart pointer does not borrow the interface, calling release decrements the reference count. If the reference count equals 0 after calling release, it destroys the object that implements the interface.

The wrapped interface is set to nullptr.

Smart pointer destructor does the same thing as release.

◆ supportsInterface() [1/2]

bool supportsInterface

Checks if the wrapped interface supports another interface.

Template Parameters

U	The interface to check for support.

Returns: True if the interface is supported, False otherwise.

◆ supportsInterface() [2/2]

bool supportsInterface ( const IntfID & id ) const

Checks if the wrapped interface supports another interface using the interface ID.

Parameters

id	The ID of the interface to check for support.

Returns: True if the interface is supported, False otherwise.

◆ toString()

ObjectPtr< IString > toString

Converts the object to the string object.

Returns: The Converted smart pointer wrapped to the IString interface.

	openDAQ Open data acquisition platform

Detailed Description

template<typename T> class ObjectPtr< T >

Public Member Functions

Static Public Member Functions

Constructor & Destructor Documentation

◆ ObjectPtr() [1/10]

◆ ObjectPtr() [2/10]

◆ ObjectPtr() [3/10]

◆ ObjectPtr() [4/10]

◆ ObjectPtr() [5/10]

◆ ObjectPtr() [6/10]

◆ ObjectPtr() [7/10]

◆ ObjectPtr() [8/10]

◆ ObjectPtr() [9/10]

◆ ObjectPtr() [10/10]

◆ ~ObjectPtr()

Member Function Documentation

◆ addRefAndReturn()

◆ addressOf()

◆ Adopt()

◆ as()

◆ asOrNull()

◆ asPtr()

◆ asPtrOrNull()

◆ Borrow() [1/2]

◆ Borrow() [2/2]

◆ call()

◆ convertTo()

◆ detach()

◆ dispatch() [1/2]

◆ dispatch() [2/2]

◆ dispose()

◆ Equals()

◆ equals()

◆ execute() [1/2]

◆ execute() [2/2]

◆ freeze()

◆ getCoreType()

◆ getHashCode()

◆ getObject()

◆ isBorrowed()

◆ isFrozen()

◆ operator T*()

◆ operator&()

◆ release()

◆ supportsInterface() [1/2]

◆ supportsInterface() [2/2]

◆ toString()

template<typename T>
class ObjectPtr< T >